Sound recording and records



A g- 9, 32. E. H. FOLEY 1,870,447

SOUND RECORDING AND RECORDS Filed July 10, 1930 IN VENT OR D ATI Patented Aug. 9, 1932 UNITED STATES PATENTOFFICE EARL B. BOLEY, OF ABIOEI'LA, NEW- YORE, ASSIGNOR TO FILITONE CORPORATION, A

CORPORATION OF DELAWARE SOUND RECORDING AND RECORDS lppliectien filed my 10,

' This invention relates generally to the recording or sound and more particularly to en improved apparatus and method especially designed for cutting a sound groove in s. flex-- recording medium. The invention also to an improved record body consistor e flexible medium having it sound. recr groove thereon.

llie recording medium which 1 preferably employ is a thin film of plssticized material such as the usual motion picture film. s l have iscovered thet e film of this. character will by the use of appropriate apparatus, progressive cutting therein of s sound record groove, which accurately represenw sound waves received by the recording apparatus. Furthermore, such a groove may Without lurther treatment he used for reproduction repeatedly Without impairment oi the sound produced.

desired, e single film may have a, large nurnher of record grooves thereon,"arrsnged lj F u side lay side, representing for example a num-.

her of separate selections. Also, sound grooves may be formed on both sides of the film, end in one embodiment of my invention employ as the recording medium an endless or continuous film and cut therein a, continuous spiral or helical sound groove along the length of the film, the pitch of the helix he ng verv slight so thet the successive turns or laps of the groove are closely spaced side i by side and the entire groove covers s largeportion or the ores of the film as suggested in the sentence beginning line 22 pogo 6, of my application Serial #21 377 died April 7th, 15. 125 on sound recording apparatus. in this manner one film muy'contsin a relatively long selection.

Also, if desired, l rosy cut the sound groove on the margin of 3.- motion picture film, which is not occupied by the picture end such groove may constitute a record of sound designed to as reproduced synchronously with the piclhis cornoined picture and sound film has many edvsnteges over the records heretofore employed for this purpose, not only with respect to its durability and efficiency as an instrument for the simultaneous pro i duction of sound and picture, particularly mo. Serial No. 467,093.

under the conditions obtaining in the motion picture art, but also with respect to the economy and simplicity of the method by which such a, combined record may be made and the edaptability of such method to present stun derd practice in the motion picture art, as is more fully explained in my co-pendingapplication Serial Number 453,295, filed May 17, 1930.

In the preferred embodiments of my inven tion the sound record groove is of the hill and dale type. in forming this groove 1 make use of an electromagnetic device of improved construction, which is provided with a cut ting tool having a cutting point lorn'ied of hard material such as diamond or sapphire, this point being especially designed for operating on relatively tough material such as a photographic film. The film is fed over a suitable anvil past the cutting point the point being held in a direction substantially tanportion similar inshepe to 2, Wood chisel and designed to form the grooveby he termede scooping action.

Further advantages and objects of my invention will appear from the following dcscription taken in connection with the accompsnying specimen and the annexed drawing, wherein: n The specimen is s strip of film formed with sound record grooves thereon.

Figure of the drawing shows in side elevstiou one form of electromagnetic recorder constructed in accordance with my invention, together with a portion of the film on which the record is being made, an anvil for supporting the film as it moves by the recording stylus and a pick-up for reproducing the sound trout the record groove es it is mode.

What may Figure 2 is an' end elevation of the recorder shown in Figure 1.

Figure 3 is a detail sectional'view taken on the line 3-3 of Figure 1. Figure 4 is a detail sectional view taken on the line 4-4 of Figure 1.

Figure 5 is a greatly enlarged sectional view of one end of the cutting tool in cutting contact with the film, showing the mounting of the cutting jewel or point, and

Figure 6 is an enlarged detail sectional view on the line 66 of Figure 3, showing the manner of joining the cutting tool operating rod to the armature of the electromagnet.

Figures 1 and 3 show my improved device in actual size except that for clearness of illustration I have shown the spacing of cer tain parts as somewhat greater than the actual spacing, as will be explained hereafter.

Referring to Figure 1, reference character 10 represents an electromagnetic recording device for making a hill and dale groove record on a film 11 which is fed in the direction of the arrow, over a curved or cylindrical anvil 12.

The device 10, which serves to control the movement of the cutting tool 14, comprises .an eleetromagnet which is adapted to be supplied with constant direct current for producing a permanent magnetic field. Secured to the magnet 20 are frame pieces 22 of magnetic material, to which are adjustably secured pole pieces 24. -Four pole pieces are employed, two on the upper frame piece and two on the lower frame piece, as shown in Figure 3. These pole pieces are screw threaded through the frame pieces so as to be adjustable vertlcally.

Mounted on each of the pole pieces 24 is a winding 26 adapted to be connected in the output circuit of an amplifier or other system controlled in accordance with the sound vibrations to be recorded. The connections to the windings 26 are such that the talking the adjacent upper poles of opposite polarity and opposed upper and lower poles also of opposite polarity. g

- Mounted to rock in the space between the pole pieces 24 is an armature 27 of Norway or otally mounted at its center on pivot bearings 29 and 30,-mounted respectively in an inner frame piece 32 and an outer-frame piece 33,

both formed of brass or other non-magnetic metal The pivot bearing 29 -may be fixed to the frame piece 32 and the bearing 30 screwthreaded through the frame piece 33 and adjustable by turning the knurled head .36. Suitable lock nuts 37 are provided to hold the pivot bearing 30 in position and, if desired,

the frame piece 33 may be formed with an internally screw-threaded elongated bushing (not shown) extendingtoward the armature currents flowing therethrough tend to make 27 so as to form an elongated rigid bearing support for the pivot bearing member 30.

Adjustably secured to the armature 27 at one side of the center of the armature is light rod 38 of non-magnetic material such as aluminum. In Figure 6'I show the connection between the rod 38 and armature 27 this onnection being designed to permit the rod 38 to maintain its vertical osition as it is moved up and down by rocklng of the armature 27. This connection comprises a disc or collar 42 which is pivotally mounted in an opening 43 in the armature 27. One side of the opening 43 is formed with an integral tapered pivot bearing 44, which is received in the bearing opening 45 in the disc 42. A corresponding opening 47 at the opposite side of the disc 42 receives the tapered end of a pivot bearing 48 which is screw-threaded into 7 one edge of the armature and carries a looking screw 50. Rod 38 is formed with a screwthreaded upper end which is received in a central opening 51 in the disc 42 and held in position by a lock nut 53. It will be understood that I may if desired employ other forms of connection between the rod 38 and armature which will permit angular movement between rod and armature, such for example as a properly designed ball and socket oint.

Rod 38 is pivotally secured at its lower end at 56 to a lever 60 of light material such as aluminum and which is snu ly pivotally secured at 59 to a downwar 1y extending rigid bracket 62 formed of non-magnetic material. The opposite end 64 of the lever 60 is flattened transversely and is desi ed to move between upper and lower ad ustable or plates of resilient meta 74, 75, respective- 66 and 67 are carried 6 ly, which are adapted to be engaged by screws 76, 77, respectively, for forcing the outer ends of the strips toward one another. Intersimilar iron of low retentivity, which is piv- Posed between the Outer ends of the strips tice the pads may be formed of rubber of I the characterof the ordinary rubber band,

and the lower pad 79 may conveniently be of double the thickness of the upper pad. In practice the screws 76 and 77 are adjusted so as to submit the pads to substantial pressure.

The

cutting tool 14 is rigidly secured to the bolt and is adapted to receive the cutting tool 14. Tightening of the nut 82 on the bolt 80 serves to clamp the tool lightly against the bottom of the lever 60, the lever being pro vided with a recess 84. to permit the collar 83 to be drawn upward and the top, of the tool forced-against the bottom of the lever.

- .The tool comprises a rod or shank 86 of metal such as brass, in one end of which is secured or embedded the cuttingpoint 87,

formed of hard material such as sapphire or diamond. As shown, this point is cylindrical in form with a concave outer end 89. In Figure 5 I show the point in contact with the moving film-and it will be seen that the edge of the cutting point which is in engagement with the film is convex downwardly, forming in effect a scoop which cuts a trench having a bottom, curved or circular-in section.

Figure 5 shows the disposition of the metal of the rod 86 around the cutting point 87, the metal above extending over the point, as

' indicated at 90, to form a bracing or strengthe'ning means to withstand the upward thrust of the point and prevent its breaking and the metal below the point being cut away as indicated at 91, so as to leave room for the passage of the film.

Inasmuch as the point 87 is very minute and can only be seen with difliculty, I curve the opposite end of the rod, as indicated at 93, preferably in a direction toward the side or overhanging part "90, so that prior to clamping the rod in position the rod may be turned in the collar 83 to correct position with the cutting point 87 in the position shown in Figure 5.

In Figures 1 and 5 it will be seen that the cutting point is normally directed along a line approximately tangential to the curve of the film as it passes over the anvil 12, also that the thrust of the moving film against the cutting point is largely taken up by the pivotal connection between the lever 60 and bracket 62 which lies almost directly back of the cutting point, this thrust having little or no tendency to change thealtitude of the cutting point. It is highly desirable that the feeding of the film past the cutting point should proceed at an even rate and as an aid to this end I preferably drive the filmby means of a friction feed (not shown).

InFigure 1 of the drawingIshow the cutting point directed away from the pivot 59 0f thelever 60 andtoward the clamping 65 pads. I may, however, operate the record.

with the cutting tool reversed, that is, pointing toward the pivot 59. In either case, however, the motion of the film is against the edge of the cutting point. The varying currents in the coils cause vibrationof the armature 27, which is transmitted through the connecting rod 38 to the lever 60 and tool 14. The magnetic forces acting on the armature 27 are increased through the leverage connection between the armature and rod 38 and serve to impart to the cutting point 87 the desired forces for changing the depth of the cutting edge below the surface of the film. Figure 3 shows one spacing of the rod relative to the pivotal center of the armature. In this figure for the purpose of clearness I have shown the coils 26 somewhat farther apart than in actual practice.

lVhile the connections 38 and '60 may be formed of aluminum, I find that to overcome the resistance offered by the film to movements of the cutting tool, these parts should not be of too light a construction, as I preferably utilize the mass or inertia of these parts in overcoming the film resistance, the cushion.

pads furnishing the desired damping. Also moving these parts,-I employ in the windings 26 currents of relatively high value. With windings of approximately 60,000 ohms impedance, I find a current consumption of appreferably adjust the pole pieces 24 toward which the armature swings when the cutting point is moved deeper into the film to a position closerto the armature than the remaining pole pieces. For a similar reason, also the lower cushion pad 79 is made less resistaant to movement than the upper pad 78, as previously described.

Reference character 98 represents an 1nsulated terminal bar which carries the binding posts 99 for connection to the external circuits. Leads 100 connect the bindingposts to the several magnetic windings of the device 10.

For the .purpose of ascertainin the quality of the sound record produce I mount a pick-up 102 close to the cutting tool, so that the sound may be reproduced from the groove as fast as the groove is cut. Any varlations from the desired quality, volume, etc. can thus be immediately detected and by making appropriate adjustments I can secure the cutting of an accurate sound record.

The accompanying specimen shows a sound record groove cut on a motion picture film.

- to provide a sufficient actuating forcefor ment is designed to produce a film adapted to hold the photographic emulsion and have the requisite mechanical strength and durability for use as a motion picture film. I find that by the use of the apparatus shown in the accompanying drawing, suitably energized by sound currents, I am able to cut progressively along such a filma groove which forms an accurate sound record, and the grooves in the accompanying specimen were cut in this manner by the apparatus shown. These grooves form sound records of portions of explanatory lectures.

The portion of the film removable by the point 87 is in the form of a clean cut strip shaved oil? from the film. Such groove may average .001 of an inch in depth with variations from substantially the surface of the film to .002 of an inch in depth. Such a groove does not appreciably impairthe strength of the film and I have been able to use such a groove record for reproduction of sound as many as ten thousand times without appreciable impairment of the sound produced. The groove cut by the apparatus shown in the drawing is of the hill and dale type and need not be more than .001 or .002 of an inch-in width, and as a result I am able, if I so desire, to place a number of these grooves side by side along the marginal portions of the film without encroaching on the area occupied by the picture to be projected. Sixteen such sound grooves may be placed on the marginal portion of the usual motion picture film outside of the area of the projected picture.

This application is a continuation in part of my copending application Serial Numbers 235,056, filed November 22, 1927, and 453,295, filed May 17, 1930.

Having now described my invention, what I claim and desire to secure by Letters Pat cut is:

1. In a device for cutting sound grooves, a vibratory supporting member, a cutting tool having an elongated shank, a clamp for removably securing said shank to said member, a cutting point of hard material embedded in one end of said shank and formed with a cutting edge at one side of said shank and means on said shank for indicating said side, so as to permit proper and ready positioning of said shank in said clamp.

2. In a device for cutting sound grooves, a vibratory supporting member, a cutting tool aving an elongated shank, a clamp for removably securing said shank to said member, a cutting point of hard material embedded in one end of said shank and formed with a cutting edge at one side of said shank, said shank being curved at opposite end for indicating said side, so as to permit proper and ready positioning of said shank in said clamp.

33 In a device for making sound grooves, electromagnetic actuating means, a lever connected to said means, a pivotal support for one end of said lever, damping means engaging the opposite end of said lever, and a cutting tool carried by said lever intermediate engaging said member and operable to resist movement of said tool in a direction away from said film, a second damping device engaging said member and operable to resist movement of said tool in a direction toward said film, said second device offering greater resistance to movement of said tool than said first named device.

5. In a device for progressively cutting a sound groove in a moving film, the combination with an anvil over which the film is moved, a cutting tool adjacent said anvil and adapted to vibrate in a direction substantially normal to said film, said tool having a cutting edge pointing in a. direction substantially along said film and against the movement of said film, a vibrating member on which said tool is mounted, a damping device engaging said member and operable to resist movement of said tool in a direction away from said film, a second damping device engaging said member and operable to resist movement of said tool in a dlrection toward said film, said second device oflering greater resistance to movement of said tool than said first named device. I

6. In a device for progressively cutting a sound groove in a moving film, the combination with an anvil over which the film is moved, a cutting tool adjacent said anvil and adapted to vibrate in a direction substantially normal to said film, a vibrating member on which said tool is mounted, a damping device engaging said member and 0perable to resist movement of said tool in a direction away from said film, a second damping device engaging said member and opcrable to resist movement of said tool in a direction toward said film, said second device offering greater resistance to movement of said tool than said first named device, and means for adjusting the damping efi'ect of each device independently of the other.

7. In a device for cut-ting a hill and dale sound record in a film, a cutting point movable in directions toward and awa said film, means for supporting saic point, a clamping device oflering relatively low resistance to said movement toward said film, and a damping device offering relatively high Eesistance to said movement away from said 8. In a device for cutting a hill and dale sound record in a film, a cutting point movfrom ' in the county of New able in directions toward and awe from said film, means for supportin sai point, and damping means ofiermg re atively hi h resistance to said movement away from and film and relatively low resistance to said movement toward said film.

9. In a device for cutting a hill and dale sound record in a film, a cutting point movable in directions toward and awa from said film, means for supporting sai point, damping means ofi'ering relatively high resistance to said movement away from said film and relatively low resistance to said movement toward said film, and electromagnetic .means for vibratin said point in accordance with the sound vibrations to be recorded and for biasing said point in said direction toward said 10. In an electromagnetic recorder, a permanent magnet, opposed pole pieces in the magnetic circuit of said magnet, operating windin on said pole pieces,a pivoted armature a apted to vibrate between said pole pieces, a. cutting tool, a lever on which said tool is supported, a pivotal sup ort for one end of said lever, a dampin evice in enga ement with said lever an an operating r0 connecting said lever and armature.

11. In an electromagnetic recorder, a per-- manent magnet, opposed pole pieces in the magnetic circuit of said magnet, operating windin tool is sup orted, a pivotal support for one end of sai lever, cushion pads at the op ositeend of said lever in enga ement with opposite sides of said other en and an operating rod connecting said lever and armature.

Signed at 50 Broadwa ork and State 0 New York, this 23rd day of June, A. D.

- EARL H. FOLEY.

on said pole pieces, a pivoted arma- 'ture a apted to vibrate between said pole pieces, a cutting tool, a lever on which'said,

, New York city by 

